(1) Technical Field
The present invention relates to voltage reference circuits and more particularly to a voltage reference circuit for use with integrated bipolar linear circuits where a temperature stable reference voltage is needed in the range of 1.2 to 2.0 volts DC.
(2) Background Art
Numerous integrated circuit voltage references are available. An example of such a device in the low voltage range of approximately 1.2 volts is that manufactured by National Semiconductor under their part number LM313 which demonstrates a temperature stability of plus or minus one percent over a temperature range O.degree. C. to 70.degree. C. However at the present time in the event of the need for a device with a negative or positive temperature coefficient other than zero, little or nothing is available to meet such requirements.
In the Gamma.TM. Telephone as manufactured by GTE Communication Systems Corporation, the desired temperature compensation was achieved with a discrete component reference using a combination of a 2.7 volt zener diode and silicon diode. This method however was not suitable for integration.